Quite a few automobiles currently manufactured in countries other than the United States, most of which have four cylinder engines, have exhaust gas systems in which one conduit is used to carry the gas emitted from two exhaust gas ports in the engine. These ports are often close to each other but it is still common practice to use two pipes to conduct the gas from the two ports to the one exhaust gas conduit, though there is a rather expensive clam shell type of adapter arrangement that has been conceived for directly connecting the one conduit to the two ports.